Hundreds of protesters marched towards the site of the United Nations climate conference in Copenhagen as world leaders prepared to meet in an attempt to broker a new global warming deal.

Climate activists, angry at the slow pace of negotiations, descended on the Bella Center Wednesday where leaders from more than 100 nations are gathering for the summit. Police say more than 100 demonstrators were arrested after breaking through a security perimeter.

Nine days of talks have produced no major breakthrough with some saying that delegates have spent too much time posturing and repeating positions rather than compromising.

British Prime Minister Gordon Brown, who is in Copenhagen for the conference, said that a failure to act could effect the quality of life for millions of people.

The White House says US President Barack Obama is confident that an agreement can be reached this week.

World leaders have until Friday to agree on a final accord for reducing greenhouse gas emissions or for financing poorer countries' efforts to cope with the effects of global warming.